Amidine sulphamates and a process for making them



Patented Dec. 9, 1941 UNITED" STATES PATENT OFFICE AMIDINESULPHAMATES AND A PROCESS FOR MAKING THEM William H. Hill, Stamford, Coma, assignor to American Oyanamld Company, New York,

N. I, a corp ration of Maine No Drawing. Application November 18, 1939, Serial No. 305,176

9 Claims.

in which Ri'and R2 are members of the group consisting of hydrogen, alkyl, hydroxy alkyl' and aryl radicals, and X is a member of the group consisting of RiOX JNRTRI 8nd HNibNRiBI The substituents R1 and R: may be the same or dlflerent in the various bases included within the scope of the invention and it should be understood that each symbol is intended to represent any member of its defined group.

An inspection of the above type formula-will show that my invention includes the sulphamic acid salts of the amidine bases contained within the group consisting of guanidine, guanylurea, guanyl guanidine and their basic reacting substitution products, which salts may be used as intermediates in the preparation of the corresponding amidine salts.

The salts of the present invention may be employed in the synthesis of other organic compounds. The salts of the unsubstituted amidines, orof the substituted amidines which have a low number of carbon atoms, may be used as flameretardants for paper or textiles. Where acidity is not undesirable the corresponding biguanid acid sulphamates may also be likewise employed. The sulphamic acid salts of amidines substituted with a long chain alkyl group may be employed as wetting agents and the substantially neutral salts of the diaryl substituted amidines may be employed as delayed action activators. in the vulcanization of rubber.

Any guanidine base of the above group may be used for the purpose, such as guanidine itself, dimethyl or trimethyl guanidine, dibutyl guanidine, mono-, dior triphenyl guanidine, ditolyl guanidine, or hydroxyalkyl substituted guanidines such as mono-, dior triethanol guanidine and the like. Similarly such guanylurea compounds as guanylurea itself, monoor di-methyl guanylurea, diphenyl guanylurea, tetra-ethyl guanylurea, and triethanol guanylurea are organic bases which will form salts of sulphamic acid.

Biguanid, and such substituted biguanids as monoand dimethyl' and diethyl biguanids, diamyl biguanids, 1.5-diallyl blguanid, 1.1.5.5- tetramethyl biguanid,'1.1.2-trimethyl biguanid, and 1.2.3-triphenyl biguanid will with sulphamic acid also form salts of the present invention.

It should be noted, however, that the biguanids, in contrast to the other amidine bases included within the scope of the invention, will form both neutral and acid salts with mineral acids such as hydrochloric, nitric and sulphuric acids. Similarly, therefore, the biguanid bases will form neutral and acid salts containing respectively one and two molecular equivalents of sulphamic acid for each mole of the biguanid. It should be understood that both classes of such salts are included within the scope of the invention.

The salts maybe prepared by simply mixing a solution containing the free amidine base or its carbonate with a solution of sulphamicacid.

' One may also start with the amidine sulphate or other mineral acid salt,from which the free base can be liberated by dissolving the salt in alcohol, adding an alkali such as sodium hydroxide thereto and removing the precipitated sodium sulphate, or other salts.

The following are examples of methods for the preparation of the amidine salts to which, however, the invention is not to be limited.

EXAMPLE 1 Guanylurea sulphamate 97 grams of sulphamic acid are dissolved in a minimum of water, which is about 300 cc. at 50 6.; then 102 grams of guanylurea free base are added slowly and with good stirring. On

cooling guanylurea sulphamate crystallizes out as a snow-white salt. I

Examrta 2 Biguanid s ulphamatc 9'7 grams of sulphamic acid are dissolved in a minimum of water,-which is about 300 cc. at 50 C. 101 grams of biguanid free base are added slowly and with good stirring. 0n evaporation ofthe water under reduced pressure at about 40-60" C.,-a white crystalline product is obtained which is biguanid neutral sulphamate.

When 194 grams of sulphamic acid are used,

EXAIPLI 3 97 grams of sulphamic acid are dissolved in a minimum or water, which is about 300 cc. at 50 C. Then 90 grams oi guanidine carbonate are added slowly and with good stirring. n evaporation of the water under reduced pressure at about 40-60 C. and cooling, guanidine sulphamate crystallizes out as a colorless salt.

The preparation of the salts is not, however, limited to the foregoing processes but in accordance with my invention guanidine sulphamate may be prepared by heating one mole of dicyandiamide with two moles 01' ammonium sulphamate to form a melt or guanidine sulphamate,

which, after cooling. may be recrystallized from water.

Such a process is claimed in my copending application Serial No. 305,176, flied November 18,

Exmu 4 A mixture oi 228 grams of ammonium sulphamate and 84 grams of dicyandiamide were heated by means of an oil bath having a temperature of 155 C. Ammonia in very small amounts was evolved from the start and at 115 C. a thin melt resulted which thickened appreciably at 125 C. At 150 C. a clear thin melt resulted and the temperature rose exothermically to175 C. whereupon the reaction mix was removed from the oil bath and allowed to cool to around 150 C.

Heating was then resumed. The mass was heated for a total or about three hours, $6 hour being taken to heat it up to about 150 C. For most or the heating time the temperature of the mass varied between 145-155 C. The product dissolved freely in water to give a solution showing a pH 01' 6.5 and analyzed about guanidine sulphamate. 0n recrystallization from water the product gave large colorless crystals of over purity.

In like manner, substituted guanidine sulphamates may be prepared from the corresponding substituted ammonium sulphamates.

What I claim is:

1. An addition salt of sulphamic acid and an organic base selected from the group consisting of the guanidines, guanylureas and biguanids.

2. An addition salt or sulphamic acid and a guanidine.

3. Guanidine sulphamate.

4. An addition salt of sulphamic acid and a guanylurea.

5. Guanylurea sulphamate.

6. An addition salt of sulphamic acid and a biguanid.

7. Biguanid sulphamate.

8. Biguanid neutral sulphamate.

9. A method of preparing addition salts of suiphamic acid which comprises reacting an organic base selected from the group consisting of the guanidines, guanylureas and biguanids with an aqueous solution of sulphamic acid.

WILLIAM H. HILL. 

